For almost 20 years, the Portland public schools have maintained a testing program anchored in locally constructed tests. The district's newly developed tests are called goal-referenced tests, a version of criterion-referenced tests, that meet the district's purposes because they reflect what well-qualified teachers in the district believe should be taught and measured. In constructing the tests, curriculum personnel select goals they believe the test should measure; teachers develop items that measure those goals; the tests are given a trial administration and items are analyzed; the items, formats, and directions are revised; and the tests are administered for their intended use. The Rasch test scaling procedure that involves the identification of an equal-interval scale of difficulty for a given set of items based on information about item difficulty and total test performance for the group tested is used. The procedure yields information on item difficulty and an estimate of the ability of individuals and groups tested. This permits establishment of a scale that is independent of the norming population and allows for the creation of item pools. (Author/IRT)